There are generally two types of shift levers for handling a vehicle transmission: a floor mounted-type shift lever installed on the floor adjacent the driver's seat and a column-type shift lever installed on a steering column adjacent to the steering wheel. In shifting operations of conventional column-type shift levers, the shift stages are generally arranged so that they progress in clockwise order of P→R→N→D→3→2→L. Thus, if a driver rotates the shift lever by a predetermined angle starting from position P (an angle toward position R), the lever consecutively moves through the different gears.
Vehicle transmissions in general are also largely divided into two types: manual transmission type and automatic transmission type. The manual transmission and the automatic transmission have their own advantages and disadvantages, respectively, on the basis of which they have been selectively installed and used according to a driver's taste. Since it is difficult to handle the manual transmission compared with the automatic transmission, and thus the manual transmission may be considered inconvenient, a recent tendency is toward preferring a vehicle equipped with an automatic transmission.
On the other hand, however, the manual transmission has an advantage in that a driver can perform gear shifting in accordance with vehicle operating conditions, so that the manual transmission has superior gas mileage over that of the automatic transmission and allows a driver to enjoy a dynamic driving feel. For the sake of drivers preferring the convenience of the automatic transmission and the dynamic driving characteristic of the manual transmission, an automatic transmission with a manual shifting mode similar to the manual transmission's gear shifting has been recently developed.
Many automatic transmission structures with the manual shifting mode have been proposed for vehicles with the floor mounting-type shift lever, but such an automatic transmission has generally not been proposed for vehicles with the column-type shift lever because it is structurally difficult to apply the manual shifting mode to the vehicle with the column-type shift lever. Some proposals also have problems regarding unfavorable handling properties due to structural complexity or poor durability.
Consequently, there is a need for developing a column-type shift lever structure capable of applying a manual shifting mode thereto.